/*
 * Copyright 2009 Mike Cumings
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.kenai.jbosh;

/**
 * Qualified name of an attribute of the wrapper element. This class is
 * analagous to the {@code javax.xml.namespace.QName} class. Each qualified name
 * consists of a namespace URI and a local name.
 * <p/>
 * Instances of this class are immutable and thread-safe.
 */
public final class BodyQName {

	/**
	 * BOSH namespace URI.
	 */
	static final String BOSH_NS_URI = "http://jabber.org/protocol/httpbind";

	/**
	 * Namespace URI.
	 */
	private final QName qname;

	/**
	 * Private constructor to prevent direct construction.
	 * 
	 * @param wrapped
	 *            QName instance to wrap
	 */
	private BodyQName(final QName wrapped) {
		qname = wrapped;
	}

	/**
	 * Creates a new qualified name using a namespace URI and local name.
	 * 
	 * @param uri
	 *            namespace URI
	 * @param local
	 *            local name
	 * @return BodyQName instance
	 */
	public static BodyQName create(final String uri, final String local) {
		return createWithPrefix(uri, local, null);
	}

	/**
	 * Creates a new qualified name using a namespace URI and local name along
	 * with an optional prefix.
	 * 
	 * @param uri
	 *            namespace URI
	 * @param local
	 *            local name
	 * @param prefix
	 *            optional prefix or @{code null} for no prefix
	 * @return BodyQName instance
	 */
	public static BodyQName createWithPrefix(final String uri,
			final String local, final String prefix) {
		if (uri == null || uri.length() == 0) {
			throw (new IllegalArgumentException(
					"URI is required and may not be null/empty"));
		}
		if (local == null || local.length() == 0) {
			throw (new IllegalArgumentException(
					"Local arg is required and may not be null/empty"));
		}
		if (prefix == null || prefix.length() == 0) {
			return new BodyQName(new QName(uri, local));
		} else {
			return new BodyQName(new QName(uri, local, prefix));
		}
	}

	/**
	 * Get the namespace URI of this qualified name.
	 * 
	 * @return namespace uri
	 */
	public String getNamespaceURI() {
		return qname.getNamespaceURI();
	}

	/**
	 * Get the local part of this qualified name.
	 * 
	 * @return local name
	 */
	public String getLocalPart() {
		return qname.getLocalPart();
	}

	/**
	 * Get the optional prefix used with this qualified name, or {@code null} if
	 * no prefix has been assiciated.
	 * 
	 * @return prefix, or {@code null} if no prefix was supplied
	 */
	public String getPrefix() {
		return qname.getPrefix();
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public boolean equals(final Object obj) {
		if (obj instanceof BodyQName) {
			BodyQName other = (BodyQName) obj;
			return qname.equals(other.qname);
		} else {
			return false;
		}
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public int hashCode() {
		return qname.hashCode();
	}

	// /////////////////////////////////////////////////////////////////////////
	// Package-private methods:

	/**
	 * Creates a new qualified name using the BOSH namespace URI and local name.
	 * 
	 * @param local
	 *            local name
	 * @return BodyQName instance
	 */
	static BodyQName createBOSH(final String local) {
		return createWithPrefix(BOSH_NS_URI, local, null);
	}

	/**
	 * Convenience method to compare this qualified name with a
	 * {@code javax.xml.namespace.QName}.
	 * 
	 * @param otherName
	 *            QName to compare to
	 * @return @{code true} if the qualified name is the same, {@code false}
	 *         otherwise
	 */
	boolean equalsQName(final QName otherName) {
		return qname.equals(otherName);
	}

}
